Hybrid powertrains for vehicles utilize different power sources under different vehicle operating conditions. A hybrid powertrain with an electrically-variable transmission that can provide an input-split operating mode and a separate compound-split operating mode typically has three planetary gear sets and one or more motor/generators. The input-split operating mode has a single transmission ratio where the motor/generators do not need to supply mechanical power to allow power to be transmitted from the input to the output, and the compound-split operating mode has two such ratios. That is, at one particular ratio of input speed over output speed in the input-split mode and two particular ratios in the compound-split mode, power is transmitted from input to output without conversion of any of it into electrical power and back again. Each of these particular transmission ratios, where power is transmitted mechanically, is sometimes called a “mechanical point”. Different operating modes are established by engaging brakes and/or clutches in different combinations and controlling the engine and motor/generators. Power-split operating modes are advantageous, as they may be used to improve fuel economy by allowing the engine to operate at its most fuel efficient speed. However, the additional components required for a hybrid powertrain, such as the planetary gear sets, brakes and/or clutches, may increase overall vehicle cost and packaging space requirements.